okay to get your ram to work at 1600 if it already isnt here is what you do enter the bios by pressing delete and move over to the cell menu option
next you'll need to scroll down until you come to the first set of ram options, should look like this.
as you can see it defaults to auto usually so my ram originally only worked at 1066mhz but when you've paid extra for the 1600 you wanna be able to use it. okay now if you press enter on the fsb ram ratio auto option and change that to 1:4 you'll be able to get 1600 like below.
hope this helps make a bit of difference bios's can be a scary and weird place sometimes